The objective of the research is to examine two issues relative to brief psychiatric rating scales: (1) Do such psychiatric screening instruments reliably measure clinically meaningful dimensions of psychopathology, and (2) do such screening devices measure the same dimensions of psychopathology across the different population segments? Data will be analyzed from a sample of 1,173 subjects interviewed in Kansas City, Missouri, in 1971-72, under the auspices of the National Institute of Mental Health, Center for Epidemiologic Studies. The sample is diverse socioeconomically and ethnically (25% Black, 75% White) and constitutes an excellent source to examine the research questions posed above. The survey instrument consisted of more than 300 questions relation to mood, mental and physical health, life changes, and demographic information. Briefly stated, the analyses will focus on the various psychiatric screening instruments included in the Kansas City study and will consist of (1) calculating item-whole correlations for each scale for the total sample, and then separately for blacks/whites, males/females, and lower/upper socioeconomic status groups; (2) calculating Cronbach's alpha for each scale (total sample, subgroups); (3) then comparing the alphas of each pair of mental health scales with the correlation coefficient between the scales (total sample, subgroups); and finally, (4) conducting a principal components analysis (total sample, subgroups) of the individual scales examined in the first three steps.